I heard Theo Bleckmann perform Duet For One at a Bar Mitzvah, his gift to the initiate.  He is both performer and composer here; the music displays his extraordinary vocal range, not to mention stamina.  Earlier today I played the Duet for Aleba Gartner, who remarked that it reminded her of my own Trapset for alto flute, both in that the notes of different registers occupy different sound worlds, and in that there is a percussive quality to those worlds.  In both cases, certainly, the low notes have a hollow, drum-with-a-skin quality.  And in both cases there is disbelief that the sounds are produced by a single human performing live.

Duet for One, Theo Bleckmann